Meanwhile, husband Alex raced back to their Utah home to see what was up.

Sully soon reverted to usual self — “wagging his tail and running around acting like himself” — though the strange cough remained. Salsberry worked from home for the rest of the day to keep an eye on the dog. He’d cough on occasion, but was otherwise normal.

The following morning, as readying for the work day began, the cough reappeared.

Again, Salsberry opted to work from home and made vet appointment for Sully. The doctor listed several conditions that might be the culprit, including kennel cough, but tests showed that Sully was healthy.

“They gave us some antibiotics just in case it was a bacterial infection, but he didn’t have a fever or any symptoms,” Longhurst said. “So the doctor was confused.”

The kept a close eye, but the cough seemed to have abated. Longhurst said the vet suggested Sully could be putting them on.

“He told us sometimes animals fake sick or limp for attention or treats or special privileges.”

Colin Allen, a professor of cognitive science at the University of Pittsburgh, told BuzzFeed News that based on his knowledge of animal cognitive behavior, he suspects Sully was not deceiving his owners, but drawing upon past learned behaviors.

“I’d be less willing to agree that it’s a deliberate deception such that the dog realizes that by coughing the owners will assume it’s sick,” Allen said. “I’m going for the explanation that it’s learned behavior.”

Longhurst tweeted about it and found that other pet owners reported similar incidents, including a cat that faked a limp and a dog that just stopped walking.

“Sully is so so, so smart,” Longhurst said. “We’ve babied him so much he knows how to play us like a fiddle…. We’re pretty sure he knows that we know he was faking it. So he is just a naughty faker who wanted some extra attention, and boy did he get it,” she said. “We baby him so much he probably learned that if he acted weird or different someone would spend the day with him.”

Longhurst says that Sully hasn’t coughed since the vet visit. “He is his happy self,” she said.